B.K. Poudyal , Y.X. Zhang, G.Q. Du, Q.C. Shi and J. Liu

DOI

ABSTRACT

The experiment was conducted to find out appropriate explant type for in vitro regeneration of adventitious shoots of pear (Pyrus pyrifolia) cv Whangkeumbae. Shoot explants were collected from the field and cultured in vitro in a Murashige and Skoog (MS) shoot proliferation medium (MS + 1.0 mg L -1 BA and 0.1 mg L-1 IBA) and continuously maintained for 8 months in vitro. Four types of explants (treatments) namely stems with leaves, stems without leaves, leaves with petioles and stems with leaves cultured in hormone-free medium were excised and cultured in shoot induction medium (MS + 0.2 mg L-1 NAA + 1.0 mg L-1 TDZ). Cultures were maintained in this medium for 21 days in continuous darkness for shoot induction and then transferred to a shoot expression medium (MS +1.0 mg L-1 TDZ) and maintained at 25±1 0C with a 16/8 hours light/dark photoperiod regime for 8 weeks. Finally shoots were transferred to a MS shoot elongation media (MS +0.2 mg BA, 0.1 mg IBA and 0.2 mg GA3). The stem explants with leaves produced highest number of shoots (87) (P≤0.001) with 100 % shoot regeneration rate. In this treatment, some of the explants developed up to 21 adventitious shoots.